The evident and the hidden factors of vitamin D status in older people during COVID-19 pandemic

Purpose

Considering the COVID-19 pandemic, vitamin D is a target of research and speculation. Lockdown or home isolation reduces sunlight exposition and increases the risk of vitamin D deficiency. Special attention is needed for older people at risk of both severe forms of COVID-19 and vitamin D deficiency. This review aims to highlight the association of vitamin D and COVID-19 in two instances, the direct influence of vitamin D on the immune system, and the indirect risks for other vitamin D deficiency-related diseases, such as musculoskeletal properties in older persons.

Methods

We performed a narrative review.

Results

Whether vitamin D deficiency is associated with COVID-19 poor prognosis, and if vitamin D supplementation may improve the post-infection outcomes is still unclear. In any case, the pandemic generates indirect burden, such as the sequence: home isolation, low sunlight exposition, vitamin D deficiency, and fragility fractures.

Conclusion

Therefore, it is time to debate how to optimize vitamin D status in older people, especially during the COVID-19 pandemic.

Rosemary supplementation (Rosmarinus oficinallis L.) attenuates cardiac remodeling after myocardial infarction in rats

BACKGROUND

Myocardial infarction (MI) is one of the leading causes of morbidity and mortality worldwide. Dietary intervention on adverse cardiac remodeling after MI has significant clinical relevance. Rosemary leaves are a natural product with antioxidant/anti-inflammatory properties, but its effect on morphology and ventricular function after MI is unknown.

METHODS AND RESULTS

To determine the effect of the dietary supplementation of rosemary leaves on cardiac remodeling after MI, male Wistar rats were divided into 6 groups after sham procedure or experimental induced MI: 1) Sham group fed standard chow (SR0, n = 23); 2) Sham group fed standard chow supplemented with 0.02% rosemary (R002) (SR002, n = 23); 3) Sham group fed standard chow supplemented with 0.2% rosemary (R02) (SR02, n = 22); 4) group submitted to MI and fed standard chow (IR0, n = 13); 5) group submitted to MI and fed standard chow supplemented with R002 (IR002, n = 8); and 6) group submitted to MI and fed standard chow supplemented with R02 (IR02, n = 9). After 3 months of the treatment, systolic pressure evaluation, echocardiography and euthanasia were performed. Left ventricular samples were evaluated for: fibrosis, cytokine levels, apoptosis, energy metabolism enzymes, and oxidative stress. Rosemary dietary supplementation attenuated cardiac remodeling by improving energy metabolism and decreasing oxidative stress. Rosemary supplementation of 0.02% improved diastolic function and reduced hypertrophy after MI. Regarding rosemary dose, 0.02% and 0.2% for rats are equivalent to 11 mg and 110 mg for humans, respectively.

CONCLUSION

Our findings support further investigations of the rosemary use as adjuvant therapy in adverse cardiac remodeling.

Vitamin D induces increased systolic arterial pressure via vascular reactivity and mechanical properties

Background/Aims

The aim of this study was to evaluate whether supplementation of high doses of cholecalciferol for two months in normotensive rats results in increased systolic arterial pressure and which are the mechanisms involved. Specifically, this study assesses the potential effect on cardiac output as well as the changes in aortic structure and functional properties.

Methods

Male Wistar rats were divided into three groups: 1) Control group (C, n = 20), with no supplementation of vitamin D, 2) VD3 (n = 19), supplemented with 3,000 IU vitamin D/kg of chow; 3) VD10 (n = 21), supplemented with 10,000 IU vitamin D/kg of chow. After two months, echocardiographic analyses, measurements of systolic arterial pressure (SAP), vascular reactivity, reactive oxygen species (ROS) generation, mechanical properties, histological analysis and metalloproteinase-2 and -9 activity were performed.

Results

SAP was higher in VD3 and VD10 than in C rats (p = 0.001). Echocardiographic variables were not different among groups. Responses to phenylephrine in endothelium-denuded aortas was higher in VD3 compared to the C group (p = 0.041). Vascular relaxation induced by acetylcholine (p = 0.023) and sodium nitroprusside (p = 0.005) was impaired in both supplemented groups compared to the C group and apocynin treatment reversed impaired vasodilation. Collagen volume fraction (<0.001) and MMP-2 activity (p = 0.025) was higher in VD10 group compared to the VD3 group. Elastin volume fraction was lower in VD10 than in C and yield point was lower in VD3 than in C.

Conclusion

Our findings support the view that vitamin D supplementation increases arterial pressure in normotensive rats and this is associated with structural and functional vascular changes, modulated by NADPH oxidase, nitric oxide, and extracellular matrix components.

Impact of the length of vitamin D deficiency on cardiac remodeling

BACKGROUND

This study was aimed to evaluate the influence of vitamin D (VD) deficiency on cardiac metabolism, morphology, and function. Thus, we investigated the relationship of these changes with the length of the nutrient restriction.

METHODS AND RESULTS

Male weanling Wistar rats were allocated into 4 groups: C2 (n=24), animals were fed an AIN-93G diet with 1000 IU VD/kg of chow and were kept under fluorescent light for 2 months; D2 (n=22), animals were fed a VD-deficient AIN-93G diet and were kept under incandescent light for 2 months; C4 (n=21) animals were kept in the same conditions of C2 for 4 months; and D4 (n=23) animals were kept in the same conditions of D2 for 4 months. Biochemical analyses showed lower β-hydroxyacyl coenzyme-A dehydrogenase activity and higher lactate dehydrogenase activity in VD-deficient animals. Furthermore, VD deficiency was related to increased cytokines release, oxidative stress, apoptosis, and fibrosis. Echocardiographic data showed left ventricular hypertrophy and lower fractional shortening and ejection fraction in VD-deficient animals. Difference became evident in the lactate dehydrogenase activity, left ventricular weight, right ventricle weight, and left ventricular mass after 4 months of VD deficiency.

CONCLUSIONS

Our data indicate that VD deficiency is associated with energetic metabolic changes, cardiac inflammation, oxidative stress, fibrosis and apoptosis, cardiac hypertrophy, left chambers alterations, and systolic dysfunction. Furthermore, length of the restriction influenced these cardiac changes.